Methods and Apparatus for Generating a Control Message Frame

Abstract

A wireless network communication device comprises a host processor, a network interface coupled to the host processor and comprising a transceiver operable to generate and transmit a control message frame. The control message frame includes: a short training field, a long training field, and a signal field including modulation and coding scheme subfield to hold message type information, transmitter address information, receiver address information, and frame check sequence information.

What is claimed is: 
     
         1 . A method comprising:
 generating a control message frame comprising a signal field (SIG) to instruct the end a contention-free period; and   wirelessly transmitting the control message frame.   
     
     
         2 . A method according to  claim 1 , wherein the said signal field is generated in response to an instruction to acknowledge a prior message and to end a contention-free period. 
     
     
         3 . A method according to  claim 1 , wherein the said signal field is used to instruct the end restricted access window (RAW) period. 
     
     
         4 . A method according to  claim 1 , wherein the said signal field comprises message type, transmitter and receiver address information, and frame check sequence information. 
     
     
         5 . A method according to  claim 1 , wherein generating a control message frame comprises at least one of:
 generating a short training field and a long training field;   generating a signal field without the transmitter address information;   generating a signal field without the receiver address information;   generating a signal field that includes a MCS subfield, optional BSSID/TA subfield, optional RA subfield, Tail subfield, CRC subfield, Reserved subfield, and FCS subfield;   generating the control message frame in response to an instruction to end an HCF (hybrid coordination function) controlled channel access period;   generating the control message frame in response to an instruction to end an enhanced distributed channel access period;   generating the control message frame in response to no more data to send at a client station;   generating the contention-free control message frame to include a group receiver address.   
     
     
         6 . A method according to  claim 1 , wherein generating the control message frame comprises generating the control message frame at an access point of a wireless network. 
     
     
         7 . A method according to  claim 1 , wherein generating the control message frame comprises generating the control message frame at a client station in a wireless network. 
     
     
         8 . A method according to  claim 1 , wherein generating and wirelessly transmitting a control message frame comprises generating and transmitting the control message frame to trigger uplink or downlink transmission for one or more client stations in a current restricted access window time slot. 
     
     
         9 . A method according to  claim 1 , wherein generating and wirelessly transmitting a control message frame comprises generating and transmitting the control message frame to trigger an uplink or downlink transmission in a next restricted access window time slot. 
     
     
         10 . A wireless network communication device comprising:
 a host processor;   a network interface coupled to the host processor and comprising a transceiver operable to generate and transmit a control message frame to end a contention-free period including:   a short training field;   a long training field; and   a signal field including modulation and coding scheme subfield to hold message type information, transmitter address information, receiver address information, and frame check sequence information.   
     
     
         11 . A wireless network communication device according to  claim 10 , wherein the transceiver is operable to at least one of:
 generate a signal field that includes a signal field without the transmitter address information;   generate a signal field that includes a signal field without the receiver address information;   generate a signal field that includes a signal field that includes a MCS subfield, optional BSSID/TA subfield, optional RA subfield, Tail subfield, CRC subfield, Reserved subfield, and FCS subfield;   generate the control message frame in response to an instruction to end restricted access window operation;   generate the control message frame in response to an instruction HCF (hybrid coordination function) controlled channel access period;   generate the control message frame in response to an instruction to end an enhanced distributed channel access period; and   generate the control message frame in response to no more data to send at a client station.   
     
     
         12 . A wireless network communication device according to  claim 10 , wherein the transceiver is operable to generate the control message at an access point of a wireless network or at a client station in a wireless network. 
     
     
         13 . A wireless network communication device according to  claim 10 , wherein the transceiver is operable to generate and wirelessly transmit the control message frame to trigger uplink or downlink transmission in a current restricted access window time slot. 
     
     
         14 . A wireless network communication device according to  claim 10 , wherein the transceiver is operable to generate and wirelessly transmit the control message frame to trigger an uplink or downlink transmission in a next restricted access window time slot. 
     
     
         15 . A wireless network communication device according to  claim 10 , wherein the transceiver is operable to generate and wirelessly transmit the control message frame to contain a group receiver address. 
     
     
         16 . A wireless network communication device according to  claim 10 , wherein the transceiver is operable to generate and wirelessly transmit the control message frame to contain a broadcast address. 
     
     
         17 . A method of restricted access window operation in a wireless network, the method comprising:
 initiating a restricted access window channel access operation; and   generating and transmitting a CF-End message frame at an access point to one or more client stations in response to an instruction to end restricted access window channel access operation.   
     
     
         18 . A method of restricted access window operation in a wireless network, the method comprising:
 initiating a restricted access window channel access operation; and   generating and transmitting a CF-End+CF-Ack message frame at an access point to one or more client stations in response to an instruction to acknowledge a prior message and end restricted access window channel access operation.   
     
     
         19 . A method of restricted access window operation in a wireless network, the method comprising:
 initiating a restricted access window channel access operation; and   generating and transmitting a CF-End message frame at a client station in response to no more data to send and to trigger downstream transmission from an access point.   
     
     
         20 . A method of restricted access window operation in a wireless network, the method comprising:
 initiating a restricted access window channel access operation; and   generating and transmitting a CF-End+CF-Ack message frame at a client station in response to acknowledging a prior message and no more data to send, and to further trigger downstream transmission from an access point.